Gene transfer into human cells is being investigated for the treatment of a variety of genetic and acquired human diseases. Genetic diseases, due to a single-gene defect, were originally proposed as the primary targets of gene therapy. However, the majority of the human gene therapy trials approved so far involve treatment of acquired diseases, such cancer and AIDS. One approach to tumor gene therapy relies on the stimulation of the host immune system against tumor antigens by vaccination of the patient with genetically modified tumor cells, in which the transgene (cytokine, allo-HLA, etc.) is aimed at boosting their immunogenicity. An alternative approach is based on the adoptive transfer of ex vivo generated tumor-specific effectors. The infused effectors are usually autologous or HLA-compatible lymphocytes stimulated in vitro to proliferate by specific as well as non-specific stimuli. Amplification of the effector function of the infused cells has been achieved by their transduction with cytokine-encoding genes.
EP 0 904 786 discloses a method of tumor vaccination with at least two subsequent administrations of a compositions consisting essentially of autologous or HLA-related cells which are capable of presenting antigen in a patient, said cells being either tumor cells transduced with a foreign gene or antigen presenting cells transduced with a tumor antigen and a foreign antigen.
WO97/19169 discloses a tumor vaccine containing tumor cells at least a portion of which has at least one MHC-I haplotype of the patient on the cell surface, and which have been loaded with an antigen.
Thus, the prior art takes the approach of using a tumor cell as the delivery system for an antigen, or an antigen presenting cell which is understood as presenting the antigen directly to a T cell.
It will be however appreciated that there is a continuing need to provide vaccines and vaccination approaches. The present invention provides such an approach.